It was my must-see TV series when I was growing up and I still love it, even though I now watch through my fingers because of the rather repetitive plots and the reactionary attitudes to women.

Not surprisingly I adored Samantha, the pretty, well-meaning witch trying to keep her magic to a minimum (to please her dullard husband). These days I see the real role model is Endora, the archly wise and glamorous ‘baddie’. But I think it instilled in me a longing for magic that never quite went away.

When I think back to the books that I loved best as a child, they were always the ones with magic in them. Much as I enjoyed the adventure stories of the likes of the Famous Five or the school stories of St Clare’s and Malory Towers, deep down I knew they would never happen to me. I wasn’t smart enough to solve a crime and I wasn’t cool, rich or sporty enough to be one of midnight-feasters at boarding school.

But magic – well, that could happen to anyone, couldn’t it?

When I think back to the books that disappointed me as a child, they were the ones that promised magic but didn’t deliver. I vaguely remember one that boasted a witch in the title, for instance, but she turned out to be a kindly old lady and it was all about not judging people by appearances. Pah – a morality tale in disguise. And there were the books that weren’t quite magic-y enough – where the magic was so small and underwhelming that it wasn’t worth the trouble.

Perhaps it’s not surprising, then, that magic keeps creeping into my own writing.

What may be surprising is that magic – in all its chaos and weirdness – almost always comes with rules.

Even those whacky Bewitched episodes had rules. If one witch casts a spell, another can’t remove it, for instance. But they can sometimes cast another spell to mitigate it – which of course takes us right back to Sleeping Beauty and the good fairies at the christening.

In my first children’s novel, The Serpent House (Curious Fox, 2014) the magic was time travel. And it turned out, as I was doing my research, that you can’t just bob back and forward through time, willy-nilly. There are all sorts of conventions and these date back to the first ever children’s time travel story, which was arguably Edith Nesbit’s The Story of the Amulet (1906).

For example, time travel can’t happen anywhere – there has to be a portal that enables the transportation, whether it’s a door or a piece of jewellery or a machine. Time moves differently in your ‘primary’ world when you’re travelling to the past (or future) – you can be away for months but find that only minutes have passed in your present day. And no matter how hard you try, you can’t (usually) change things in the past because it has too severe an effect on the future. You can mess with these rules – writers always like to try - but you’re asking for trouble.

The Misper (Conrad Press, 2018) wasn’t meant to be at all magical. Aimed at ages thirteen-plus, it’s primarily about friendships and it’s set in present-day Normal Town. But then my characters started trying magic out and it was hard to stop them (teenagers, you know). And things began to happen. I leave it up to the reader to decide whether the magic’s real or whether it’s all in Anna and Zoe’s heads.

Something I have noticed in my writing is that magic rarely ends well. If this is another rule, then I’m not sure why it is - I feel so sure that if someone gave me a wand for a day I’d do all sorts of good with it. But maybe it’s the subliminal message I picked up from Bewitched at an impressionable age: that really, you shouldn’t meddle with what is normal and natural. It’s high time I ditched that notion and let more magic in – wouldn’t you agree?